Question

我想知道如何获取对象数组中多个数组的总和。我的代码如下：

const employeeList = [    

    {
    "name": "Ahmed",
    "scores": [
    "5",
    "1",
    "4",
    "4",
    "5",
    "1",
    "2",
    "5",
    "4",
    "1"
    ]
    },
    {
    "name": "Jacob Deming",
    "scores": [
    "4",
    "2",
    "5",
    "1",
    "3",
    "2",
    "2",
    "1",
    "3",
    "2"
    ]
    }];

var sum = 0;

for(let i = 0; i < employeeList.length; i++){
  var eachScore = employeeList[i].scores;
  const b = eachScore.map(Number);
  console.log(b);

  sum += parseInt(b);//this is the code that doesn't work

}

console.log(sum);

所以问题是，我可以将两个数组放入控制台日志，但是我不确定如何对每个数组求和。.当我执行sum + = parseInt（b）时，它只会记录多少个项目在array（9）中。当我不使用parseInt时，它会将数字合并在一起，但不对它们求和。.我想使用.split（）方法拆分数组并将它们分别求和，但我还没有弄清楚做到这一点。

Answer 1

由于b是一个数字数组，因此除非您需要逗号连接的字符串，否则您无法将+与它配合使用。总结数组的最实用方法是使用reduce，该数组可用于迭代其项并将其全部添加到累加器中：

b.reduce((a, b) => a + b);

如果您想知道部分和，我将使用.map通过提取employeeList属性并将scores数组中的每个对象转换为其分数总和。使用reduce对它们进行总计：

const employeeList=[{"name":"Ahmed","scores":["5","1","4","4","5","1","2","5","4","1"]},{"name":"Jacob Deming","scores":["4","2","5","1","3","2","2","1","3","2"]}]

const sum = (a, b) => Number(a) + Number(b);
const output = employeeList.map(({ scores }) => scores.reduce(sum));
console.log(output);
// If you want to sum up the results into a single number as well:
console.log(output.reduce(sum));

Answer 2

您可以使用array reduce来计算总和：

const employeeList = [    
{
  "name": "Ahmed",
  "scores": [
  "5",
  "1",
  "4",
  "4",
  "5",
  "1",
  "2",
  "5",
  "4",
  "1"
  ]
},
{
  "name": "Jacob Deming",
  "scores": [
  "4",
  "2",
  "5",
  "1",
  "3",
  "2",
  "2",
  "1",
  "3",
  "2"
  ]
}];

var sum = 0;

for(let i = 0; i < employeeList.length; i++){
  let eachScore = employeeList[i].scores;
  let b = eachScore.reduce((total,current)=>{
    total += +current;
    return total;
  },0);
  console.log(b);

  sum += b;
}

console.log(sum);

Answer 3

也许这会有所帮助：

var parsedScores = [];
var scores = [
   "4","2","5","1","3","2","2","1","3","2"
];
let total = 0;
scores.forEach(el => {
   parsedScores.push(parseInt(el))
})
for (let score in parsedScores) {
   total += parsedScores[score]
}
console.log(total);

如何获取对象数组中多个数组的总和？

3 个答案: